The present disclosure relates to the art of measuring objective refraction, and, more particularly, to a retinoscopy rack or paddle, axis compass, and method of integrating or adapting same.
In known arrangements, a retinoscopy rack or paddle (or sometimes referred to as a “ret rack”) is used with a retinoscope for example by an associated eye-care practitioner such as an optometrist or ophthalmologist (sometimes referred hereinafter as “professional”) to assess a range of refraction error and also to assess a limited axis of astigmatism in the eyes of a patient as part of an optical examination. A beam of light is passed from the retinoscope through one of the lenses in a retinoscopy paddle into the eye of a patient while the patient views a distant object, allowing the professional to examine how light is reflected off the retina of the patient. The error of refraction can be determined by using a retinoscopy paddle that includes or holds a series of lenses typically in an ordered fashion, that is the lenses of different strength are preferably arranged in the paddle in a progressive or orderly fashion to aid the professional in positioning a particular lens over the eye of the patient, and then quickly and easily positioning a different lens of a different optical strength over the eye. The professional can evaluate the patient by alternately and selectively directing light through one of the lenses, and then viewing through a lens of a different optical strength, e.g., greater or lesser degree of optical strength, until the retinal reflex is observed as being in a desired or normal range through the retinoscope.
Existing retinoscopy paddles lack the ability to measure oblique astigmatism angles, that is, existing retinoscopy paddles are generally limited to measuring the axis of astigmatism at angles of 90 and 180 degrees exclusively. With existing retinoscopy paddles, the associated professional must hold the retinoscopy paddle at an angle to determine the best acuity setting for the patient, but lacks a quick, convenient, accurate, and efficient method of also measuring the astigmatism angle. When using an existing retinoscopy paddle, the associated user must use a separate, second device, such as a phoropter, to attempt to replicate the angle. This method can become burdensome and time consuming for the associated professional.
It is desirable to provide a retinoscopy paddle that neither compromises the highest quality of measurement with expediency and nor is as time consuming, burdensome, or inefficient as using existing retinoscopy paddles and a separate device to evaluate or measure oblique astigmatism angles.